Labour
Conservative
1987
11.83
20.06
1992
18.58
21.55
1997
24.46
16.33
2001
19.85
13.68
2005
17.71
16.56
2010
17.67
17.86
2015
19.57
21.71
2017
26.08
21.91
2019
26.06
19.08